Three HMRC statutory instruments take effect on 30 June and 1 July 2026, bringing the most significant customs changes for importers since EU exit: a 50% import duty on steel products replaces the outgoing 25% safeguard, two procedural instruments introduce new £2,500 penalties and reshape obligations for port operators, customs representatives, AEO holders, and carnet users.
Three statutory instruments made under the Taxation (Cross-border Trade) Act 2018 and the Customs and Excise Management Act 1979 come into force on 30 June and 1 July 2026. Together they represent the most consequential package of UK customs changes since the post-EU-exit regulatory settlement came into effect.
The headline measure — S.I. 2026/572 — replaces the expiring UK steel safeguard with a 50% standard import duty on specified steel products. Unlike the old 25% safeguard-plus-tariff-rate-quota regime, the new duty overrides preferential and zero-rated treatment under most trade agreements, with a single exception for goods originating under the UK–Ukraine partnership. Steel importers, downstream manufacturers, and public-sector procurement bodies all face a materially higher cost base from 1 July.
The two procedural instruments — S.I. 2026/604 and S.I. 2026/605 — take effect the day before, on 30 June. Between them they update AEO (Authorised Economic Operator) security criteria, broaden customs-representative accountability, extend digital carnet submission, and require port operators to provide off-site customs examination facilities at their own cost. Both introduce a flat £2,500 penalty for specific new obligations. If your business touches any of these areas, the changes demand attention now.
Who this applies to: importers of steel products across the 20 categories previously subject to the UK safeguard; downstream manufacturers and fabricators who use steel inputs; and public-sector procurement bodies procuring steel-intensive works or goods.
The UK steel safeguard — a 25% tariff plus tariff-rate quotas across 20 steel product categories — expires on 1 July 2026. The government has chosen not to renew it; instead, S.I. 2026/572 introduces a 50% standard rate of import duty on "excepted goods" (the steel products in those 20 categories, covering approximately 100% of domestic steel production) as listed in the new Excepted Goods Table in version 1.32 of the Tariff of the United Kingdom, dated 25 May 2026. The duty is applied on a national-security rationale under powers in section 8(9) of the Taxation (Cross-border Trade) Act 2018, as amended by the Finance Act 2026, and was made by the affirmative procedure.
Critically, the 50% duty overrides preferential rates, quota entitlements, and zero-rated duties that would otherwise apply under UK free trade agreements or the British Overseas Territories regime. The sole exception is goods that qualify as originating under the Political, Free Trade and Strategic Partnership Agreement with Ukraine — these retain their preferential rate. If you have been relying on a preferential tariff under another trade agreement for steel imports, that relief is extinguished from 1 July.
Transitional relief: the new duty does not apply to goods imported before 1 October 2026 in satisfaction of obligations under contracts that were entered into before 13 March 2026. To benefit, both conditions must be met: the contract must pre-date 13 March 2026 and the goods must clear customs before 1 October 2026. Importers with qualifying contracts should act promptly to document their position and ensure shipments land in time.
Who this applies to: AEO holders and applicants (particularly those handling air cargo); customs representatives; freight carriers; and operators of any means of transport arriving in the UK.
S.I. 2026/604 makes three substantive changes to the customs safety and security regime in Great Britain (Northern Ireland customs arrangements remain governed by the Windsor Framework). First, it updates the criteria for Authorised Economic Operator — Security and Safety (AEOS) status by replacing references to aviation security legislation that is being revoked with references to the Aviation Security (Air Cargo Agents) Regulations 2024. Regulated agents and known consignors handling air-transported goods need to verify that their AEOS conditions are satisfied under the updated criteria.
Second, HMRC's obligation to disclose AEOS authorisation data to the Civil Aviation Authority (CAA) is converted from mandatory to permissive. Third — and with immediate financial consequence — the instrument introduces a new £2,500 penalty under Article 133 of the assimilated EU regulation for operators of means of transport who fail to notify HMRC of their arrival in the UK. The instrument also clarifies that penalties for safety and security declaration failures apply to customs representatives of the declarant as well as to the declarant, broadening accountability across the customs clearance chain. Finally, "Exit Summary Declarations" are renamed "Pre-departure Declarations" throughout the relevant Schedule.
Who this applies to: port operators; importers and exporters using ATA or CPD carnets; postal operators; businesses with outstanding customs duty; Channel Tunnel operators and users.
S.I. 2026/605 makes five substantive changes with effect from 30 June 2026. The most structurally significant is the first: HMRC may now require port operators to provide customs examination facilities at approved off-site locations where the port itself lacks adequate space. This replaces the government-funded Inland Border Facility model with a direct commercial obligation on port operators. Contravention of these new approval conditions carries a £2,500 penalty. Port operators should review their facility arrangements and existing HMRC approval conditions now.
The second change benefits carnet users: ATA and CPD carnets may now be submitted in electronic form, with digital carnets carrying equivalent legal status to paper versions for customs declaration purposes. This modernises the temporary import regime and reduces administrative burden for frequent carnet users such as exhibition organisers and touring companies.
The remaining three changes are: a clarification of how HMRC calculates interest on outstanding customs duty liabilities (particularly where declarations are found incorrect after goods are released); an extension of the simplified bulk declaration process for imported postal packets to Northern Ireland recipients (previously available only for Great Britain); and a new £2,500 penalty for breach of Channel Tunnel customs conditions under Article 3 of the Channel Tunnel (Customs and Excise) Order 1990.
Take the following actions before and immediately after these instruments come into force:
An explainer of the post-EU-exit UK customs framework: how import duty arises, the role of the Taxation (Cross-border Trade) Act 2018, and the main 2018 Regulations that govern declarations and debt.
Step-by-step guide to submitting an import declaration on the Customs Declaration Service, including data elements, procedure codes, and authorisation requirements.
How to claim a reduced or zero tariff rate on goods imported under a UK free trade agreement, including rules of origin, proof of origin, and CDS preference codes. Note: preferential rates are overridden by the new 50% steel duty for most agreements from 1 July 2026.
How to speed up border clearance with Simplified Declaration Procedure, Entry in Declarant's Records, AEO status, and Customs Comprehensive Guarantee.
How to decide whether you need a customs agent, choose the right type, and set up the necessary authorisations in CDS — relevant given the broadened penalty liability for customs representatives from 30 June 2026.
Your legal obligations as an importer bringing goods into Great Britain, including customs duty, import VAT, and commodity code classification.
An audit checklist to work through before your goods arrive at the GB frontier, covering declarations, duty classification, origin, licences, and record-keeping.
A strategic explainer of the customs debt regime, civil penalty tiers, and criminal offences under the Customs and Excise Management Act 1979 — essential reading given the new £2,500 penalties introduced by these instruments.
Guide for freight forwarders and customs agents on representation obligations, customs warehousing, and dangerous goods in transit — includes the customs representative liability framework.
How to obtain import licences for controlled goods, including which authority to apply to and application processes.